Memorandum submitted by Tidal Electric
1. Tidal Electric Ltd (TE) is currently
developing three1 tidal power plants in the UK using its new technological
approach to tidal power generation2. These projects will be the
first-ever embodiments of the offshore impoundment structure approach
to tidal power. The UK has very large tidal ranges and many suitable
sites for further installations that could conceivably generate
thousands of megawatts.
2. TE's technology involves an offshore
impoundment structure, segmented into three or more compartments
and fitted with conventional low-head hydroelectric generating
equipment. The equipment is commonly available from numerous manufacturers
and it is a reliable mature technology that is capable of mechanical
efficiencies in the 95 plus per cent range and is performance
guaranteed by its manufacturers with a design life of 50 plus
years. There are many thousands of similar turbine/generator sets
currently installed in river applications. Similar bulb-type turbine/generator
sets are in use at the LaRance Tidal Power Station in St Malo,
France and these units have been in operation since 1965 and are
only now beginning to show signs of age.
3. The impoundment structures will be built
using conventional marine construction techniques. The most likely
material to be used is locally obtained loose rock, sand and gravel,
although other materials may be used, if circumstances require.
The impoundment structure will be segmented into separate cells
in order to provide flexibility to the operator to optimise generation
by phasing output from each of the cells. TE has developed a computer
simulation model with which various generation schemes can be
simulated, optimised and studied. The simulation model has achieved
a load factor of 62 per cent and output can be generated 81 per
cent of the time.
4. The oceans' tides are highly variable
but precisely predictable using mathematical formulae that can
calculate tidal behaviour as far into the future as required.
Similarly, the hydroelectric generating equipment is mature and
its output efficiencies are known throughout its head range.3
Using British Admiralty tidal data, the output from the tidal
generator is predictable down to 6-minute increments for as far
into the future as desired. Predictability of output is important
when integrating the output into a grid system and lack of predictability
has been a drawback for other sources of renewable power.
5. TE's technology has never been built
before and bears the inherent risks of unsuspected problems arising
despite thoroughgoing engineering planning. In order to consider
investing in such a venture, a private investor must see sufficient
return to absorb potential cost overruns, operational problems,
and other unpredicted negative events. The value of the Renewables
Obligation Certificate (ROC) provides that extra revenue and is
the key to attacting investors. Without the ROC, TE's technology
would require some form of grant and/or subsidy support to achieve
competitiveness. With the ROC, TE's technology is apparently competitive.
TE's technology, together with the ROC, has proven itself sufficiently
promising to attract private investment on each of its three proposed
projects.4 Other investors have expressed interest in future projects.
The only apparent remaining potential roadblock to commercial
viability is the consents process. Careful monitoring of the initial
projects will indicate the accuracy of projections and actual
performance will determine whether future projects would be competitive.
6. TE's technology has the potential to
make significant contributions to helping the Government reach
its targets for greenhouse gas emissions reduction. The ROC and
the Renewables Obligations on electricity providers creates enough
assistance to make initial projects commercially attractive to
private investors. Thus, while the existing support is critical
to the viability of TE's contribution to renewables in the UK,
no further assistance is required at this point. Therefore, we
suggest that tidal power need not be a higher priority, just as
long as it does not become a lower priority. Should preliminary
cost projections prove to be significantly underestimated, TE's
technology could require further grant or subsidy assistance.
7. All research and development of TE's
technology is currently funded privately. Focus is on the three
active projects in Wales and studies are being planned and initiated
as necessary preconditions for filing Planning Applications for
the three projects. TE may apply for public funds to support its
research and development activities at some point in the future,
but its near-term needs are being met with private funds.
8. The installation of a tidal generator
will impact its surrounding area by changing the behaviour of
currents and waves, which will, in turn, change existing sediment
transport regimes. It will be important to build sediment transport
models that will dictate design parameters to designers so that
the structure will not deposit more sediment in shipping channels
or increase the removal of beach sands. ABP Research Ltd has been
engaged to undertake such studies for the Swansea Bay Project.
It is expected that their considerable expertise in the field
of sediment transport modeling, combined with the fact that ABP
owns the ports of Swansea and Port Talbot, will produce a carefully
crafted design that does not disrupt the sediment transport regime
of Swansea Bay. Similar efforts will take place for the other
9. The impoundment structure for the tidal
generator will be constructed of locally obtained loose rock,
sand and gravel and it will have a natural appearance, similar
to existing shoreline coastal defense projects. Upon construction,
the impoundment structure will quickly become a habitat for many
species from micro-organisms on up through the food chain. It
will provide nesting habitats for the avian community and it is
expected that it will increase biodiversity in the area and provide
a safer habitat for some of the endangered species in the area.
Careful and complete studies of the environmental impact will
be conducted prior to Planning Application, throughout construction,
and during operations, so that future projects can be guided by
the experience of these initial projects. The projects have already
created considerable interest in the academic environmental community
at such institutions as the University of Wales (Bangor) Institute
for the Environment. It is expected that the projects will become
focal locations for many academic research studies.
10. The operation of the turbines will create
some localised turbulence. Mature fish can sense the underwater
pressure wave that the turbulence creates and will avoid the area.
An occasional fish will be swept through the turbines and 94 per
cent of these unlucky few will survive. It should be noted that
this is a very different situation from a conventional dam across
a river that anadromous5 fish must navigate, first when outmigrating
and again when they return to spawn. Every one of these fish must
pass through the turbines twice. While mortality rates are the
same whether the turbine is in a dam across a river or in the
tidal generator, far fewer fish will go through the tidal generator's
turbines and fish mortality will be orders of magnitude lower
for the tidal generator.
11. The tidal generator will be sited in
shallow water because its power source is the difference in water
levels caused by the tides and all its power is located between
high tide and low tide. Any construction below low tide is merely
for the purpose of supporting that part of the structure that
is above low tide and, therefore, it is an unproductive expense
and will be minimised. Shipping lanes require the greatest depth
available and, therefore, the tidal generator and the shipping
lanes are unlikely to be in the same place. However, the tidal
generator's impoundment structure will be fitted with suitable
nautical warning devices.
12. The North Wales coastline is hostile
to pleasure boats because of its high tides and strong wind and
wave regime. The installation of a tidal generator impoundment
structure is being hailed by local boatmen as a boon to their
business in that it will create a large area of calm water in
which pleasure boats can moor and marinas can operate.
13. The UK is the sole location under consideration
for TE's tidal generation technology. This is due to the fact
that the UK has very large tidal ranges, it is densely populated,
and the Government has created ROC's to enhance the economics
of renewable technologies. Given a successful start in the UK,
TE expects to broaden its deployment of its technology to many
high tidal range areas of the world.
Fifoots Point Tidal Power Plant
14. In April 2000, TE and AES Electrical
Ltd (a subsidiary of AES Inc, the world's largest independent
power producer) signed an agreement under which a 30 MW tidal
power project will be developed near Fifoots Point in the Bristol
Channel of the Severn Estuary. AES owns a 360 MW coal-fired power
station at Fifoots Point and the two power plants will share management
staff, facilities, and a 400 MW grid connection.
15. The first phase of the engineering studies
is underway: Harza Engineering is adapting the Tidal Power Generation
Simulation Model (intially built to model TE's tidal power project
in Alaska) to the tides in the area of Fifoots Point. Harza has
run two potential configurations and is working on a third. Each
"run" involves the virtual operation of the system,
complete with mechanical losses, using the tidal predictions at
six-minute increments for the year 2003. The output is an accurate
calculation of generation totals and instantaneous output, thereby
giving enough data to refine the configuration.
16. After defining an output curve, the
development team will issue an RFP for the power and determine
what price can be expected and thereby determining the project
economics. The engineering team will be chosen and studies will
commence. It is expected that the studies will take six months
to complete and a Planning Application will then be submitted
to the DTI. Planning Approval could be reasonably expected within
six to 18 months, whereupon construction can commence.
17. The construction of a tidal power plant
is divided into civil works and equipment manufacture. The equipment
will be manufactured by a turnkey contractor such as ABB or GE
and is estimated to take about 16 to 18 months. The civil works
schedule is planned to take two years in order that the two components
might finish at roughly the same time. There is considerable flexibility
in the civil works scheduling as the amounts of material required
per day are well within the capacity of several potential suppliers,
such as Hanson Aggregates. There has been discussion of using
ash from the Fifoots coal power station, slate waste, steel slag,
and other "waste" type materials that presumably would
be less expensive. TE has recruited the RSPB to assess the potential
impacts of the use of these materials and the economics of using
these materials would have to be compelling for them to be included
in the design. Assuming a one-year timetable until Planning Approval
and a two-years construction schedule, the Fifoots Tidal Power
Project could be in service in mid-2004, but a more conservative
would be 2005.
Swansea Bay Tidal Power Plant
18. TE has an agreement to develop a 30
MW tidal power plant in Swansea Bay (Wales) in co-operation with
the Environment Trust (http://www.envirotrust.org/index.htm),
a non-profit charitable trust that believes in the community ownership
of utilities. Most recently, the Environment Trust was responsible
for the renovation and development of Mile End Park in the East
End of London, a complex and multi-faceted project that involved
the local community on a ground floor planning level.
North Wales Tidal Power Project
19. The coastline of North Wales has been
fighting a losing battle with erosion for centuries. Rising ocean
levels and global climate change have sped this process and the
people of North Wales feel justifiably threatened by the Irish
Sea and its relentless march inland. TE has been working with
a consortium of political and environmental groups in North Wales
in order to identify and conceptualise a tidal power project that
will be configured in such a manner as to help resist the forces
of erosion and the periodic flooding that has devastated the area,
most notably in the so-called Towyn Floods of 1990. Such a configuration
will provide 432 MW of power and provide coastal defence along
the vulnerable area.
20. A core group of supporters has been
identified for the North Wales Project, including a local county
councillor, a Friends of the Earth campaigner, a wind power developer,
the Mayor of one of the local villages, and TE CEO Peter Ullman.
This group is exploring the various possible secondary on-shore
projects that will enhance the tidal power project. The tidal
power plant in France gets 600,000 visitors per year and the North
Wales group is anticipating an increase in the tourist traffic
from visitors to the tidal power plant. They are eager to add
attractions such as a sea-life museum, an education centre, and
the like. Transportation and housing are also of concern to the
21. TE is in advanced discussions with Conoco
Global Power Ltd and it is anticipated that a Joint Development
Agreement will be signed in March, 2001, and the joint venture
will develop the North Wales project.
1 Swansea Bay (30 MW), Fifoots Point (30
MW), North Wales (432 MW).
2 TE has expertise regarding its technology,
but claims no expertise in wave power, tidal stream (marine currents)
technology, or barrage tidal power. Therefore, evidence will be
limited to its area of expertise.
3 Hydroelectric generating equipment operates
by allowing water at different levels to pass through and turn
its turbine runner. Head Range is a range of water levels
(head) through which it operates. Each point in that range has
a differing mechanical efficiency, due to the differing amount
4 Fifoots Point (AES Electric Ltd), Swansea
Bay (Environment Trust Associates Ltd), and North Wales (Conoco
Global Power Ltd in negotiation, expected signing in March, 2001).
5 Anadromous fish, like salmon and
smelts, live part of their lives in fresh water and part of their
lives in salt water and must go from one habitat to the other
or die trying.
8 February 2001